The Relationship of Watersheds in the United States

The United States is divided into 21 geographic watershed regions. These regions are major drainage areas

of large bodies of water like the Gulf of Mexico. The regions also include the drainage areas of major rivers like the

Mississippi River. They are also the combined drainage areas of a series of rivers. These 21 regions are also further

divided into 221 subregions. These subregions include the drainage area of river, a reach of a river and its tributaries,

a closed basin, or a group of streams forming a coastal drainage area. These subregions are also further divided into

accounting units and 2264 cataloging units. The cataloging units are part of a surface drainage basin, a combination of

drainage basins, or a district of hydrologic features (Relationship Between Watersheds in the U.S.A.).


Major ecosystems also exist within various watersheds in the United States. There are ecosystems in the river or stream itself.

In these there are producers like algae and, photoplankton, and seaweed. Then small snails, crayfish or minnows are

predators to the producers and they are prey to bigger fish like carp or trout. Waterfowl and other organisms that fish

like bears or even people can also affect the ecosystem as predators(The Watershed Ecosystem).





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